1. Field of the Invention
This invention relates generally to the field of hand tools and more particularly to an apparatus for the marking and cutting of construction materials, wherein the apparatus is adapted for use with a measuring tape.
2. Description of the Prior Art
Sheet materials such as drywall and plywood are commonly used in the construction industry. These sheet materials are usually supplied in selected sizes, such as 4 feet.times.8 feet. When installing these sheets it is often necessary to cut or mark strips of uniform width and this is generally accomplished by using a utility knife or a pencil, in conjunction with a measuring tape. The end of the tape measure is held against the side of the utility knife or pencil with the thumb and the tape is extended across the sheet to the desired width, holding the tape reel against the edge of the sheet. With the tape reel held in one hand and the knife or pencil in the other, both hands are moved down the sheet simultaneously such that the knife scores or a pencil marks a line parallel to the edge of the sheet. In the case of drywall, after scoreing the one side, the final cut is then made without the tape measure by using the knife along the scored line. The sheet is subsequently bent along the scored and cut line until it breaks, resulting in a strip of the desired width.
The method described above is awkward and inaccurate and various devices and methods have been designed by others attempting to solve these problems. For example, U.S. Pat. No. 5,542,184 (Beard, 1996) discloses a tape measure knife attachment for cutting drywall, utilizing the end segment and angled tab of a measuring tape in line with an extended knife blade. U.S. Pat. No. 5,206,965 (Rowley, 1993) discloses a knife having a housing with a thumb positioning structure associated with elongated sides. A measurement means is held in place against the thumb positioning structure by the users thumb. U.S. Pat. No. 4,993,093 (Goldwitz, 1991) discloses a utility knife having an elongated slot extending in the same plane as the cutting blade. The angled tip of a flexible ruler is retained within the elongated slot. U.S. Pat. No. 4,949,462 (Spencer, 1990) discloses a drywall device which includes a sleeve for slideably mounting on a stem of a T-square. A knife holder containing a knife is joined with the sleeve of the '462 patent. U.S. Pat. No. 4,903,409 (Kaplan et al., 1990) discloses a drywall scribing and scoring tool which includes a knife holding unit and scribe, units for attachment along an arm of a T-square. U.S. Pat. No. 4,255,856 (Mackie, 1981) discloses a utility knife having an attachment which permits the tape of a tape measure to be directly coupled to the knife. U.S. Pat. No. 2,952,025 (Johnson, 1960) discloses a knife which includes a reel containing a measuring tape and a guide structure at the outer end of the tape.
Known prior art, as exemplified by the above referenced patents, does not provide an adequate means to firmly hold a measuring tape in order to facilitate the marking and cutting of construction materials. For example, the cutting devices described in '184 '965 '093 '856 and '025 patents hold the end segment or angled tab of a measuring tape with an extended knife blade in line with the angled tab. In order to make a cut the user guides the measuring tape at an exact dimension along the edge of the work piece while simultaneously guiding the cutting device across the work piece. This process can be very awkward and prone to slipping from the desired dimension along the work piece edge. Furthermore, the prior art does not provide a means for the marking of construction material
The '462 and '409 patents utilize T-squares. It is well known to those skilled in the art that the users of cutting devices and marking devices prefer that these devices are small to easily fit in a user's pocket or tool belt, enabling the user to move unencumbered on a construction site. T-squares for use with marking or cutting devices commonly have a relatively long arm or stem thus not fitting in the user's pocket and generally unsuitable for a tool belt.
Accordingly, the need exists for a marking and cutting device that firmly holds a measuring tape in preparation for marking and cutting of construction materials having improved ease of use and improved cutting accuracy.